Fix Titles and mkdocs nav order

courses/index.md

@@ -10,8 +10,8 @@ In this course we are focusing on building strong foundational skills. The cours
 
 - Linux basics
 - [Git](https://linkedin.github.io/school-of-sre/git/git-basics/)  
-- [Linux networking](https://linkedin.github.io/school-of-sre/linux_networking/intro/)
-- [Python](https://linkedin.github.io/school-of-sre/python_web/intro/)
+- [Linux Networking](https://linkedin.github.io/school-of-sre/linux_networking/intro/)
+- [Python and Web](https://linkedin.github.io/school-of-sre/python_web/intro/)
 - Relational databases (MySQL)
 - NoSQL concepts 
 - [Big Data](https://linkedin.github.io/school-of-sre/big_data/intro/)

mkdocs.yml

@@ -25,12 +25,6 @@ nav:
     - Python, Web and Flask: python_web/python-web-flask.md
     - The URL Shortening App: python_web/url-shorten-app.md
     - SRE Aspects of The App and Conclusion: python_web/sre-conclusion.md
-- Systems Design:
-    - Introduction: systems_design/intro.md
-    - Scalability: systems_design/scalability.md
-    - Availability: systems_design/availability.md
-    - Fault Tolerance: systems_design/fault-tolerance.md
-    - Conclusion: systems_design/conclusion.md
 - Data:
     - Big Data:
         - Introduction: big_data/intro.md
@@ -39,6 +33,12 @@ nav:
         - Evolution of Hadoop: big_data/evolution.md
         - Architecture of Hadoop: big_data/architecture.md
         - Tasks and conclusion: big_data/tasks.md
+- Systems Design:
+    - Introduction: systems_design/intro.md
+    - Scalability: systems_design/scalability.md
+    - Availability: systems_design/availability.md
+    - Fault Tolerance: systems_design/fault-tolerance.md
+    - Conclusion: systems_design/conclusion.md
 - Security:
     - Introduction: security/intro.md
     - Fundamentals of Security: security/fundamentals.md